General Question

What do you think about string theory?

I do research in the field, and am interested in the perception that people outside of the physics community have of the theory. There have been a number of flurries of publicity for the theory (see “The Elegant Universe”, “Not Even Wrong”, “The Trouble with Physics”), from which I suspect it is very hard to construct a realistic picture of what the status of the field really is. I’d also be interested to know what forms the basis for your current opinion.

20 Answers

I have read “The Elegant Universe” and a few others and I still find String Theory mostly incomprehensible (and the Nova program did not help at all). My confusion is further compounded by the “on again/off again” general acceptance of the theory as supported by the scientific community. My strengths tend to be more in the biological sciences and so my exposure to mathematics/physics theory is largely limited to popular culture.

Ha, hi Nerfmissile. I don’t have much faith in the surfer’s explanation of the universe, although I hope he’s onto something.

Chris, do you just want our perceptions? My unwashed and nearly completely useless knowledge of string theory: Somehow the universe (or matter?) is made up of strings… but I don’t know what strings are. And my impression is that string theory is very complex and completely unproveable. So I am somewhat skeptical of the theory, even though I know nothing about it. My information comes from reading random articles on the internet, possibly including a contrarian article or two on Slate.

syz—I’m not surprised that you get confused by the “on again/off again” aspect of the way the theory is presented to the public. It would indeed be very confusing if this was what was going on in the actual community! Unfortunately, I think that people are done a disservice by the amount of sensationalism that appears when string theory is popularized. In fact, there has not been the drastic changes in the status of the theory since maybe 1995, when a number of conceptual barriers were overcome and our understanding of the theory increased dramatically.

nerfmissile – i agree, if something as simple as this Lisi model could solve the problems potentially solved by string theory, it would be great! Unfortunately, i think the press re: the E8 model is again an exercise in sensationalism. There are some very deep problems in the model that Lisi proposes, which he does not address. It would be nice if they could be worked out, but he has given no indication that there is a way to overcome them.

bob – I’m happy to get your perceptions on what the theory is made of, and also what impression you might have about the status of the theory as far as being confirmed/ruled out/“untestable” as you say.

hossman – one should slow down before calling something untestable in science. Indeed, it has proven an impossible task thus far to extract predictions from string theory which could falsify the theory. It is often a misconception that this is due to an a priori untestability of the theory. The problem, rather, is that the theory seems to be incredibly deep, and our understanding of it today is still only superficial. Yet, it has still been able to provide answers to conceptual questions which no other theory of particle physics has been able to resolve before. This is the reason we work on it! However, the ultimate will absolutely have to be an experimental one, and so we need to improve our understanding of the theory to the point where precise predictions can be mad—this is all part of the research program. When that test comes, if it is found to be in contradiction with experiment, or if there comes a proof of a priori untestability, the theory, it will be abandoned—quite the hallmark of science.

I didn’t call anything untestable. I quoted someone else. Nothing you have said above about string theory does not also apply to Religion. In fact, thank you for the statements above, all of which are descriptive of Religion. One could also say that Religion is incredibly deep, and our understanding only superficial, yet has provided answers to conceptual questions no other theory has been able to resolve. Just like much of Science, the fact Religion is not testable does not mean it is not true. Everything you have stated above is ALSO “quite the hallmark of Religion.” This is the reason we work on it. Undoubtedly, if any religion could be tested and proved untrue, it would be abandoned by most, while some adherents would remain; the same is true of Science.

hossman—I apologize, i wasn’t trying to put words in your mouth. I suppose i’d rather avoid having this thread become a science/religion post – i imagine there are already some of those on fluther. I will just point out that in my mind (i’m sure people will feel free to disagree with me), the place where the analogy you’ve constructed breaks down is where I assign some truth value to the theory. While string theory (and other speculative ideas in science) can show a great deal of promise for one reason or another, we (or should I say “I”? I cannot speak for all scientists) do not seriously assign truth to the theory until it can be tested.

You (meaning Science) don’t seriously assign truth to the theory until it can be tested? Really? You can say that with a straight face? Then why the concerted efforts by Science to censor Intelligent Design and promote Evolution, when both are unprovable theories? Why the repeated denial of most of Science to recognize neither Science nor Religion have a monopoly on truth, nor is one more provable than the other. Then why do so many in both Science and Religion insist on believing they are mutually contradictory and exclusive, rather than recognizing both are merely different paths to answering many of the same questions? Why the insistence of so many “there is no question” about global warming? Seems to me Science is frequently more close-minded and fanatical than Religion. How many careers has Science ruined because one of its members dared to be creative in unacceptable manner? Probably as many as Religion has persecuted for heresy. String theory shows no more promise to explain reality than many religions.

Most importantly, your suggestion that truth is a function of testability is itself dependent upon huge assumptions about the validity of testing to reveal reality. “Proof” and testability may themselves be based upon false logical steps. The fact that a dropped pencil falls to the ground may be “proof” of gravity, but that relies upon an assumptions about our ability to perceive that are themselves not necessarily true. Perhaps the earth sucks. Perhaps the millions of angels dancing upon the point of the pencil (to borrow a famous illustration) are guiding the pencil down as part of some Grand Plan. The same test would be successful for any of these scenarios.

hossman, the differences and similarities between religion and science just isn’t the point of the discussion here—that connection, if it exists, is tangential at best to the string theory question. That doesn’t mean it’s not a question worth considering.

Agreed. Probably should be its own thread. I got lead astray by the temptation of your phrase “very complex and completely unproveable,” which is a more honest approach to science than most.

On the other hand, many physicists acknowledge and find useful the similarities between theoretical physics and religion. Some recognize similarities between various religions’ accounts of Creation and accepted theories of The Start of Everything. String theory itself has many elements not far from various theologies. Perhaps the Jesuits have something to their traditional approach that Science and Religion can each learn from the other.

First of all, I want to thank all of you for being so thoughtful and inquisitive. What a joy it is to be able to share ideas in a democratic online forum with intelligent life! Humans are so cute when inquisitive!

Oh nos:

Q: “Then why the concerted efforts by Science to censor Intelligent Design and promote Evolution, when both are unprovable theories?”

A: Science doesn’t censor; guns don’t kill people. Evolution is easily observable in patient human timeframes in fruit flies and other organisms with relatively short reproductive phases: light-shaded moths turning darker to blend in with tree bark sullied by soot at the advent of the English industrial age (think smokestacks) ... the fruit bodies of plants selected for larger, more colorful fruits by humans over time. Etc. etc. etc. Evolution is a theory in the way yo momma is a theory. Chances are, she gave birth to you… and if she didn’t, then someone else with two X chromosomes probably did. Need I mention the fossil record? Vestigial limbs in cetaceans? Anyone? No?

Q: “Why the repeated denial of most of Science to recognize neither Science nor Religion have a monopoly on truth, nor is one more provable than the other.”

A: Science and math have proofs. Religion does not. Science is based on observation, facts and reproducibility of experimental data. Religion has faith, and lots of talking heads driving Mercedes and Lexuses (what is the plural of Lexus?) so that the respective denominational flocks can feel more special than thou.

Q: “Then why do so many in both Science and Religion insist on believing they are mutually contradictory and exclusive, rather than recognizing both are merely different paths to answering many of the same questions?”

A: Mystery—>myth—>story—>the human imagination—>curiosity—>inquiry—>systematic inquiry—>science. Science wouldn’t exist without the need to ‘sci’ ... meaning, without mystery and myth, religion and unproved theories: we wouldn’t need science if we were omniscient. I’d relegate myth, story, fiction and religion to a place—useful nonetheless—preceding, and less significant than, systematic inquiry and science. Isn’t it wonderful, though, that we have both day and night? Yin and yang?

Q: “How many careers has Science ruined because one of its members dared to be creative in unacceptable manner?”

A: So true. “Experts” have their turf to defend. If you make your living monopolizing the press and promoting your name, you can’t let the upstarts belly up to the watering hole. But that’s more of a consequence of economy, biology and competitive behavior… in other words, the societal context in which science operates… than science as an endeavor per se.

Dear Chris:

So I prefer scientific sensationalism to pro sports. I find more hope panning for new knowledge than Thog throw ball… shamelessly, to the extent of being an advocate. And in fact, it turns out that E8 and Lisi’s predecessors, using multi-dimensional math, have been able to successfully predict the mass of particles to accuracies greater than that of competing theories. That’s a hat feather that’s hard to ignore… it means that E8/Heim Theory (which someone will eventually figure out are related, I hope) is actually more useful than string theory, when applied, today.

Evidently, nerfmissile, Science is your Religion. You greatly overestimate the probative value of the “proofs” you mention. Just as past scientists vehemently asserted the “truth” of their own theories, only to have them eventually disproved. If you choose to believe it is so, then it has value to you, but don’t try to persuade me it is the Truth. As an example, even many Darwinists have abandoned the tired old white/black moth illustration. Even if this were true, it only supports natural selection, change within the same species, not evolution itself, or change from one species to another. You cite the fossil record, which curiously is filled with huge gaps, yet no one asks why the fossils that would be valuable evidence of one species evolving into another are always the ones that are missing. Evidence of natural selection is not proof of evolution, nor does it disprove intelligent design. In fact, natural selection could certainly be part of an intelligent design. You mention vestigial limbs in cetaceans, but where are the intermediate fossils with intermediate limbs? But this is the sort of willful blindness that leads me to conclude scientists operate on faith just as much as theologians. Science willfully chooses to only examine the evidence that supports its theories in the very manner for which Science attacks Religion. I’m not the only one coming to these conclusions, a greater number of highly qualified scientists are inexorably lead to intelligent design by their own application of the scientific method to the available evidence.

Perhaps you should look to the recent work of Antony Flew, probably the greatest atheist philosopher and lecturer of the modern era, who has now, through an application of the scientific method to the fossil record and other evidence, has grudgingly come to the conclusion that some sort of intelligent Deity created this universe. Quite simply, evolution is a remarkably weak theory, far weaker than intelligent design, and any scientist who honestly applies critical thinking is likely to be drawn to the same conclusion. Of course, this is not a conclusion that any particular religion is true, but merely the logical conclusion that anything this complex could not occur without some cohesively compelling force.

You also might wish to examine the hackneyed stereotypes you assert about Christians. Your comment about Mercedes and Lexii is cheap and offensive. I don’t know what ministers you’re associating with, but the ones I know typically drive very old Hondas and Buicks. I do agree with you that science is and should be about facts and reproducible experimental data, that is precisely why evolution is bad science.

Science isn’t a religion. Scientific theories can be tested and proven. Gravity exists. But it’s interesting to think of some scientific theories as having something common with religion. At the outskirts of scientific knowledge, where our theories are incomplete or (yet) unproven, scientists work to prove and disprove their knowledge. They’re trying to find empirical grounds for their conjectures. (Even if some theories remain unproven, the goal is to prove them.) The fact that string theory can’t be tested is a serious fault. Religions don’t tend to want or need that empirical proof.

I don’t dislike religion. And it is important to recognize that science can be dogmatic—closed off to new theories, and dismissive of anything unscientific. But saying that science is like religion offends both science and religion; it reduces science and religion to faith without knowledge.

Bob, you’re discounting the academic work that many religious scholars do in theology, by the same processes, working to find those theories that work and those that do not. Perhaps I am being more philosophical than you, but nothing can be proven, in science or religion. You cannot prove gravity exists. You can observe the effects of gravity, you can postulate theories, but you cannot prove that mass attracts mass any more than you can disprove tiny gremlins push objects toward each other.

I don’t particularly find “provability” to be a fault with string theory, evolution, religion, philosophy or any other concept. As I do not believe anything can be proved, then the next step is to find those theories which strike myself and others as being particularly logical or elegant in explaining what we observe. Since you cannot even demonstrate the accuracy of any observation, you cannot prove the deductions based upon the observation.

I don’t think you dislike religion either. I don’t dislike science, I’ve spent way too much time devoted to it to dislike it. I do believe there are theories that appear to more logically and elegantly address observation than others. But none of this that we call reality can be proven to be real. I do believe Religion frequently has an edge on Science because Religion says “This is what I believe to be true” while Science is arrogant enough to try to say “This is what I know to be true.” This results in scientists having to be hypocrites when experimentation proves their theories to have been “wrong.” As an example, science mocked those physicians who suggested leeching was not an effective medical treatment. Later, science mocked those physicians who suggested leeching could be an effective medical treatment. Now, science is forced to acknowledge they were wrong, then they were wrong again, but now they insist they must be right. Modern science is so vehement in eliminating all contrary thought that I suggest modern science has largely abandoned intellectual openness, academic honesty and the scientific method itself.

The scientific community has, in my opinion, tragically lost one of the greatest assets it had during the Enlightenment: it has lost that understanding that it is a brother pursuit to Religion and Philosophy, that all are simply an attempt to know the unknowable and explain the unexplainable. Instead, Science has deluded itself into concluding it is somehow superior and more intelligent than the other two. You think string theory is difficult to conceptualize? Try to keep track of the varying theological theories concerning the Trinity. Or predestination. You think scientists have a monopoly on scientific method and intellectual analysis? I know a few Jesuits I’d like you to meet.

I am in the IT business with a passing interest in science and technology. I read “Scientific American” and “New Scientist” from time to time.

My impression is that we are on the verge of a great breakthrough, one that will merge all aspects of string theory and loop quantum gravity.
I feel that these are all correct, even though they seem to contradict each other.
Whether there are really “strings” and “branes” I don’t really know. They work as mathematical models for whatever the hell is really going on, for now anyway.

Remember that 100 years ago, scientists thought the atom was like a solid sphere of positive charge, with electrons embedded through it like raisins. They weren’t wrong exactly, just not refined enough. That model served its purpose and so do the current ones.

I am certainly going to stay out of the bulk of this argument, since it isn’t what I was trying to address here. I will make one point because it misrepresents the way science is applied in a deep way. hossman, you say

”. . .Science is arrogant enough to try to say ‘This is what I know to be true.’ ”

Science says no such thing, and scientists who say that are stepping outside of the realm of science in doing so (we may disagree, but I emphatically believe that the scientists out there who will make the statement you attributed to them are in a very small minority in the community). In science, we present a theory / framework / hypothesis the goal of which is to explain the physical phenomena we observe and predict future behavior. The subsequent statement which is made is

“I believe theory X to be the best current explanation of phenomena Y, Z, W which is consistent with current observations.”

If, at a later time, experiments prove to be in contradiction with the theory / framework / hypothesis, it is abandoned or revised in order to yield a more accurate theory. The fact that scientists will vigorously defend their theories does not make them “hypocrites” if the theory is shown to be wrong. Having people arguing to the best of their abilities on both sides of the debate is part of how scientific progress is made. When people step outside of the scientific method and stop arguing on the basis of science, evidence and reason, that is something that people are doing, not science (as nerfmissile pointed out). Again, you and I will probably disagree on the frequency with which modern scientists step away from the scientific method, but I wanted to clarify my thoughts on what science does and says.

When I say Science, I am referring to it as a generality, not to individual scientists, thus of course I am stereotyping broadly. Science does, however, say these things, especially when they sneer at alternative viewpoints. The condescending approach, say, to Eastern alternative medicine, intelligent design, and other politically “incorrect” approaches is nothing new. You are correct, I am indeed referring to people, not the “pure” scientific method, but I find academia is moving further and further away from the “pure” scientific method, as they abandon much of what the Enlightenment and early scientists developed. I have no problem with a scientist advocating their theories, it is their ridicule of the opposing theories that is hypocritical, and you need look no further than the “scientific” debates regarding climactic change.